


Unexpected

by appleapple



Category: Shingeki no Kyojin | Attack on Titan
Genre: Canon Compliant, Canon Era, Crack, F/M, First Time, Fluff and Angst, Genderswap, Girl! Eren, M/M, PWP, Smut, pure filth
Language: English
Status: Completed
Published: 2016-04-07
Updated: 2016-04-07
Packaged: 2018-05-31 22:12:42
Rating: Explicit
Warnings: Creator Chose Not To Use Archive Warnings
Chapters: 1
Words: 8,997
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/6489346
Author URL: https://archiveofourown.org/users/appleapple/pseuds/appleapple
Summary: <blockquote class="userstuff">
              <p>The one where Eren turns into a girl.</p>
            </blockquote>





	Unexpected

It happened on a routine mission outside the Walls. If Eren’s life was in danger he was allowed to transform; the female Abnormal they encountered certainly qualified. She had already killed two Scouts before he transformed, and he went after her in a rage, killing her with a savage bite to the neck before anyone could intervene. 

Hanji was the first one to reach him.

“Hey! That’s great, Eren, you freed yourself without even needing us! You’re getting much better at transformations.”

“Squad Leader,” Eren said. He stepped off of his rapidly-evaporating Titan, and nearly overbalanced when his feet hit the ground.

“I feel--strange,” he said.

“Strange? How so?” Hanji asked. She came closer to him, and the usual grin she wore slowly faded from her face. “Oh. Eh. Hrrrrrrm…” she said.

“What is it?” he asked. Hanji was staring at him, and he looked down, following the direction of her gaze.

He didn’t remember screaming later, but Jean told him he had, and that he’d screamed like a girl. 

Which made sense.

 

 

“So,” Erwin said. Hanji and Levi sat across the table from him. “Any ideas?”

“Well, we’ll obviously have to run a lot of experiments!” Hanji said, cheerfully. “But for all we know, this could be a standard part of Titan shifting! Or maybe it’s something unique to Eren. Or that female Abnormal--we just don’t know yet!”

“What kind of experiments?” Erwin asked.

“Oh, well I was thinking he’d have to try killing other Titans the same way--biting the necks, and seeing if that changes him back.”

“You’re sure he can’t change back on his own?”

“That’s what we’ve been trying, the last two days,” Hanji said, shaking her head. “Without success so far. He said he doesn’t know how to change back--he doesn’t even know how he changed in the first place.”

“Mm,” Erwin said. “Levi?”

“I told you it was a bad idea to go without me,” Levi said, coughing into a handkerchief. He’d been ill with the flu during the last mission, and he had shaken his head over the sorry state of their return.

“It would have still happened if you’d been there,” Hanji said, nettled.

“No,” Levi said, unperturbed. “I would have killed that female Abnormal before it got anywhere near him.”

“Putting that aside for now,” Erwin said, holding his hands up for peace. “Hanji, do you have any realistic timeline for his transforming back?”

“Well, I don’t really know,” she said. “It all depends on how our next mission goes.”

“You can wait until I’m better,” Levi told her, getting up to take his leave of them. “I have no faith in your leadership abilities.”

She glared after him while Erwin coughed his amusement into his hand.

 

 

Levi had seen for himself how miserable Eren was. The girls were sympathetic while the boys were sniggery.

It didn’t help that the girls all took him into their confidences now--offering advice on subjects that Eren had been, until now, blissfully unaware of. The right way to bind your breasts up so they didn’t bounce around when you used the maneuver gear--the best way to wrap yourself up so you didn’t bleed onto your uniform during your monthly period. How to deal with bloating--cramps--it got worse and worse, and when Sasha started telling him about what she called, _“Period shits”_ and Historia and Mikasa had nodded knowingly he had just walked away without speaking.

The boys--particularly Jean, but Connie was nearly as bad--treated it like the funniest practical joke ever. They talked to Eren as if he were still male--making all the same filthy jokes that were so amusing to an outsider, but crushingly painful when _you_ were the one in the female body. Armin was sympathetic, but clearly flummoxed by Eren’s new body, which made him too uncomfortable to want to talk to his friend about his problems.

It got bad enough one night at dinner--after another discouragingly unsuccessful day of experimentation with Hanji--that Eren leaped across the table to throttle Jean. He knocked Jean’s chair over and started strangling him.

Jean was much stronger than Eren now, and what previously would have been a fair fight quickly turned in Jean’s favor. He had flipped Eren over and was straddling him, and he got in one good punch back before Levi crossed the room and kicked him off.

He hadn’t wanted to interfere before this, and risk humiliating Eren further, but this was taking things a little too far.

“Jean,” he said calmly, “Apologize to Eren for your behavior.”

“But--” Jean protested, clutching his ribs where Levi had kicked him, “He punched _me_ first!”

“Why did he do that?” Levi asked curiously.

Jean set his jaw, looking a little flustered. For the first time he realized that he might have stumbled into dangerous waters.

“I--just--complimented him on his Titan form,” Jean muttered. At the table, the others snickered.

“Mikasa,” Levi said, “would you have punched him, if he had said that about you?”

“No,” Mikasa said. “I’d have kicked his teeth in.”

“I wouldn’t say that to Mikasa!” Jean protested. “She’s--she’s a real girl!”

“I don’t know why you would say that to any of your teammates, unless you’re a fucking piece of shit moron,” Levi said, still in that casual conversational tone. “Is that what you are, Jean?”

“No!” 

“Then apologize.”

“I’m--sorry, Eren.”

To the others at the table Levi continued, “I think you’ve had your fun. I thought you were all grown-up enough to handle yourselves, and treat your friend with the kind of respect and sympathy I’m sure you’d want to receive if you found yourself in an awkward situation.”

The others--even the girls--looked suitably chagrined.

“Apparently that isn’t the case, so consider this your only warning. If I hear anything else from the rest of you, we’ll have a little _private_ conversation about it. Understand?”

He received a lively chorus of, “Yes, sir!”

Later that night when he was alone in his room there was a knock. He was ironing his laundry and he looked up in annoyance, but he set the iron to the side to go and open the door.

Eren was standing there, looking sheepish, and he moved aside to let him in. The area around his eye was bruised and purple, and he found himself absently wishing he’d kicked Jean a little harder.

“Why hasn’t your eye healed up yet? It normally would have by now.”

Eren shrugged, uncertainly. “I don’t know. Maybe it’s something to do with--” he waved an embarrassed hand at his body, taking in the breasts and hips.

Levi pursed his lips. His healing abilities were also slowed when he was under a lot of stress or strain, but he didn’t say that.

“What happened?” he asked instead, going back to his stack of shirts.

“Do you think I could have my own room?” Eren asked. “Just until Hanji fixes me,” he hurried on, as if he expected his request to be immediately denied.

Levi made himself take a couple of breaths before answering, then he asked calmly, “Where are you sleeping now?”

“Well--still in the boy’s dormitory.”

New recruits didn’t have their own rooms, and Levi’s Squad was no exception. He had still been laid up in bed when they’d returned from their recent mission, and no one had even told him about Eren’s most recent ‘transformation’ until the next day, to his intense irritation. Hanji had still been in charge. It was so blindingly obvious that Eren should have been given his own room for the time being that he hadn’t even thought to check to make sure Hanji had done it.

“Is that the first time you hit Jean?”

Eren looked a little embarrassed. “Uh, yeah…”

“You must be growing up,” Levi said. “I didn’t think you had so much self control.” He put down the iron and set aside the shirt he’d finished, then he went to the wardrobe to take out a set of sheets.

“Come on,” he said. There were a few empty rooms near Levi’s. They bunked new recruits together for many reasons, but a lack of space wasn’t one of them. The Corp hadn’t been at full strength in a long time, and though there were few upsides to this one of them was that Levi could enjoy a little peace and quiet, and the rooms near his were usually empty.

But because they were near his he knew that they were clean, which was more than he could say for the empty rooms on the other floors. 

He led Eren down the hall, to the room that was closest to the shared washroom. “You can share the bathroom with me,” Levi said, putting the sheets down on the bed. 

Eren was staring at him open-mouthed.

“Was there something else?” he asked mildly.

“No! Just--I didn’t think it would be that easy.” He took a deep breath. “Thank you, sir.”

“Don’t worry about it,” Levi said. He paused for a moment, then said, “If you need help I’m here, Eren,” before going back to his own room, leaving Eren in stunned silence.

 

 

“He said that?” Armin said, amazed, the next day when they were training.

“Yes!” Eren said in a shrill whisper. They were practicing sparring in the courtyard the next day, and he’d given Armin a fuller account of what had happened the night before. “I thought for sure he’d blame me for doing something stupid. The way everyone else seems to. But he was really nice about it.”

“That’s...really weird,” Armin said, and then they had to stop talking when one of the officers yelled at them for goofing off.

They picked up the threads of their conversation later on, after another depressingly uneventful afternoon of experiments. Normally Levi’s Squad would be there to watch, but today Levi had caught each of them after lunch and assigned them extra duties, so it was only Hanji and her Squad and Levi. He hadn’t had a chance to talk to Armin again until later.

“I think he did that on purpose,” Eren said. 

“To punish us,” Armin agreed glumly. He and Connie and Jean had spent all afternoon mucking out the stables. “I didn’t do anything to you, did I Eren?” Armin asked plaintively.

Eren blushed, and protested, “I didn’t tell him anything!”

“Well, he seems serious about it, anyway,” Armin said, collapsing in a heap on a chair. “I don’t think anybody’s going to mess with you anymore.”

And Eren was glad about that, but he would have preferred to just not be a freak to begin with. Or at least, back to his usual level of freakishness.

 

 

The next day they went outside the Walls to continue Hanji’s experiments. Erwin and Levi both wanted to keep casualties to a minimum, and so it was only Hanji’s and Levi’s Squads that went out. They spent all day tracking down Titans for Eren to kill, and Hanji made him transform after each one to see if there was any difference.

They found regular male Titans easily enough, and even a few Abnormal males, but there was no change. Female Titans were less common, but eventually they did find one. There was no change then either.

Though they searched most of the day, they couldn’t find another Abnormal female, and eventually Levi said they’d have to head back. 

Eren forced himself to stay on his horse despite his exhaustion. He had lost count of how many times he’d transformed that day, and he felt depressed to the point of tears. 

“Don’t worry, Eren!” Hanji told him cheerfully. “I’m sure we’ll find an Abnormal female to test the next time we head out!”

But what if that didn’t work either? Nothing Hanji had thought of had so far. He was beginning to think he’d be stuck in this body forever. And there was nothing wrong with it--it was a perfectly nice female body, one that he was sure he would have admired if it had belonged to somebody else.

It just wasn’t his body.

He had experimented with it of course--that first night he’d been able to sleep alone in the new room he had touched himself everywhere. But it had been a curiously frustrating experience. It had left him feeling like he was trying to operate some complicated piece of machinery without any idea of how it worked. 

Sometimes something he did would feel good--and then a minute later it would just feel weird or uncomfortable or even painful, so he’d more or less given up. It was depressing. The one good thing about having this body for a (hopefully) short time should have been fooling around with it, but he _couldn’t_ because he _didn’t know how_. It was like having a beautiful racehorse you couldn’t ride, or a cold beer you couldn’t drink; in other words, totally useless.

And he was rubbish at fighting now. He knew what to do, but he didn’t know how to do it. His body didn’t respond the same way when he told it to do things--he couldn’t punch as hard, or as effectively, he couldn’t move as fast. His center of gravity was all screwed up, and it was hard to relearn how to use the 3DM when everyone else was so proficient. Flopping around like a little trainee in front of everyone made him die a little inside, and so he’d stopped going to practice with the others. He’d waited for the inevitable scolding, and for Levi to drag him back out to participate, but he hadn’t.

He’d been relieved.

After they got back to the castle he slept for sixteen hours, and the next day, instead of getting up and finding the others he stayed in bed, stuck in his stupid useless body, and he wallowed for a while in self-pity.

Towards evening there was a knock on the door--and he knew from its bright cheeriness who would be on the other side.

“Hi, Squad Leader,” he said, letting Hanji into the room.

“Eren!” she said, swanning in. “I have an idea! Something that might change you back.”

He sighed, internally, because so far none of Hanji’s ideas had worked.

She told him what it was.

 

 

It took two more tries, but they finally found a female Abnormal. Unfortunately for Eren, there was still no change. 

The silver lining, Levi supposed, was that they were all getting some good field experience and there had been no casualties so far. But he saw the look of abject disappointment on Eren’s face when he left his Titan form after killing her, and found his body still unchanged.

“Four eyes,” he told his friend in an undertone, “You’d better find a way to fix him.”

“I’m working on it! Don’t think I’ve given up, I still have some ideas,” she said cheerfully, and she rode over to Eren to interrogate him about this latest transformation.

The other upside was that Eren’s transformations were getting quicker and more efficient. He could almost always pull himself out of his Titan form on his own now, and he was able to exit more quickly and precisely each time. He was also less tired after coming out of it, and he didn’t need to collapse as soon as they got back to the castle.

Even so, Levi’d expected him to make an early night of it. He was surprised when Eren knocked on his door that evening, and he padded over to open it.

It was late; he’d been planning to go to bed soon himself. He’d already changed into his pajamas, but Eren was still dressed in his uniform, and Levi surveyed him, wondering what new terrible thing was happening.

“What is it?” he asked.

Eren swallowed--his face was a little red. “Hanji--has an idea about turning me back,” Eren said.

“Okay,” Levi replied, because some response seemed expected of him.

Eren blushed even more deeply, and he squirmed. “She says--” he was spitting out the words painfully, as if each one was made of broken glass, “She says, maybe if I try,” and here he mumbled something totally inaudible.

“If you try what?” Levi asked. He was still behind, and had no idea of the danger he was in.

Eren covered his face with his hands, so that he wouldn’t have to look at Levi, and said, “If I try having sex with a guy!”

For a moment Levi was too thunderstruck to speak. “You--” he started. Because there was only one reason Eren could possibly be here right now he stopped, and physically took a step back.

“Can’t you ask somebody else?” he asked, in mild horror.

Eren scrunched up his face and shook his head--but of course, Levi realized numbly, he couldn’t. Who would he ask? There was no one appropriate--not that _he_ was, but that little asshole Jean for instance, would never let him live it down. And Erwin? One of Hanji’s team, with Hanji watching nearby and no doubt taking notes and making suggestions? Armin, who was like his brother?

Another horrible thought occurred to him; Hanji had made them go through every permutation of Titan killing she could think of to try to get Eren back to normal.

_Suppose she got it into her head that he just hadn’t slept with enough, or the right number, of men to change back._

“Can’t you just stay a girl?” he asked, as alarmed on Eren’s behalf as he was appalled by the idea of taking on the task himself.

Eren stood there for a moment, quivering, and then he nodded and turned to go back to his own room. But not before Levi saw one single solitary pathetic tear slide down his cheek.

Levi stood there for a minute, feeling supremely aggravated with Hanji, who was turning out to be the cause of all of life’s problems. Then he thought of Eren, going back to no doubt childishly cry himself to sleep, having just been rejected by the one person who didn’t treat him like a freak. 

And he was even more of a freak than usual these days.

It had also been brave of him to even come here and ask, Levi thought. The more so because he’d seemed totally unsurprised by Levi’s reaction, so he’d obviously expected it before he’d even set out.

God damnit.

He’d also told Eren that he could ask him for help. He had.

God _damnit_.

“Eren,” he said. “Come back here.”

Eren froze, his back still turned, and then he wretchedly walked back as if he expected a beating.

“Come on,” Levi sighed, and pulled him into the room, shutting the door and locking it behind him.

 

 

 

Before he could even say anything Eren ruined everything by bursting into tears. Levi sighed, because of course. As if this weren’t all bad enough Eren was going to make it worse by doing the terrified crying virgin routine.

Resigned to all of it he picked Eren up and dropped him on the bed.

This wasn’t something he would have ever chosen. Eren wasn’t his type. Not that he had a type, but if he did it would be-- _older_.

Eren wasn’t bad looking, as a girl or a boy, but even if Levi had been inclined in that direction (he wasn’t) Eren had nothing on Mikasa and Historia’s head-turning beauty. There were plenty of girls in the Survey Corp that were prettier than he was, and Levi hadn’t looked twice at him, as either sex. The blotchy crying was definitely not helping.

He pulled Eren’s boots off while he sobbed and occasionally apologized.

Then he sat on the bed next to Eren, and gently took his face between his hands, and kissed him.

He was mindful of the fact that he was going to have to teach Eren how to do this, and he did it the same way he taught everything--slow, measured, careful.

Slowly Eren’s arms came up, of their own accord, to wrap around Levi. Levi nibbled Eren’s lips open, and Eren moaned into his mouth. He’d stopped crying.

Levi chased Eren’s tongue into his mouth, and once he’d gotten the hang of things he let Eren take the lead.

And Eren learned the same way he learned everything else--determined, single-minded, stubborn.

He’d always been a quick learner.

Levi pulled away after a while, and he picked up a handkerchief to wipe Eren’s face, then he handed it to Eren pointedly.

“Sorry,” Eren murmured, and blew his nose.

Levi brooded, wondering how to proceed. It hadn’t been as hard to talk his body into doing this as he’d anticipated. He wasn’t sure how he felt about that.

“Are you sure you want to do this?” Levi asked.

“Y-yes.”

“Eren. Are you _sure_. It probably won’t work. Most of Hanji’s harebrained schemes haven’t.”

“I want to try,” Eren said softly. “But I don’t want you to if--if--”

“Don’t worry about me,” Levi said, taking the used handkerchief out of Eren’s hands where he was crumpling it up and abusing it, and tossing it aside.

“If we’re going to do this we’re talking about it first. Okay?”

Eren nodded glumly.

“If you want to stop, say so,” Levi said bluntly. “I don’t care what we’re doing. You don’t owe me anything--not sex, not an orgasm, _nothing,_ okay? Don’t make me guess what you want.”

Eren nodded, and Levi glared at him.

“Yes--okay. I’ll tell you if I want you to stop. I will.”

“If something hurts then _tell me.”_

Eren swallowed. “I will.”

“If you want me to do something then tell me. Faster, slower, harder, deeper, gentler--you can do that, right?”

Eren nodded. “Yes.”

Levi sighed. “Get undressed,” he said, and Eren did, plucking nervously at his shirt, unbuttoning it slowly to expose the smooth creamy breasts tucked underneath in their tight camisole. He tugged his pants off of his fuller hips, and he fussed over his clothes, folding them and putting them aside, not looking at Levi’s nakedness. He had pulled his own shirt and pants off, and was leaning back, impatiently waiting for Eren to stop screwing around.

A new thought occurred to him.

“Eren,” he said, “Come here.”

Levi had noticed he was still wearing a longer pair of boys’ briefs, rather than the shorter underwear that was standard issue for girls. He still had the camisole on too.

He stood up, taking Eren into his arms and letting him put his head on his shoulder.

“Eren,” he said, “did you want me before? Before this?”

Eren shivered. “Yes,” he whispered.

“Before you changed.”

“Yes. I’m sorry,” Eren said, almost inaudible.

“Don’t be,” Levi said. He was relieved. This was a whole lot easier to handle if it was something Eren had wanted to begin with. Still morally dubious at best, but not the out and out ravishment that Levi had been contemplating with distaste.

“But you don’t--”

“Huh?”

“You didn’t want me,” Eren said miserably. “I don’t want to make you--”

“It doesn’t matter,” Levi said, and he kissed him again. “I want you now.” He took one of Eren’s hands and guided it over his smooth, hard-muscled abdomen through his dark pubic hair, down to his waiting cock.

He heard Eren’s sharp, nervous little exhale of breath, and he nodded to himself. It wasn’t exactly enough to give him a clean conscience, but was his conscience ever _really_ clean anyway?

He started kissing along Eren’s neck, coaxing him out of the camisole while Eren sighed and gasped, and when they were free he cupped Eren’s breasts in his hands. They were heavy and soft, and Eren gave a little hiccupy gasp of happiness when he had palmed them.

“What did I tell you,” he prompted.

“Yes, I like it, you can do that,” Eren said immediately, as if he were afraid Levi would stop otherwise. Levi smiled reluctantly against the side of Eren’s neck. 

“You can look at me,” he told Eren, and Eren shivered and looked. Tentatively he reached out to stroke Levi’s arms and back. Levi didn’t spend a lot of time thinking about his body, but he knew it was powerful and he knew what it could do. He knew he could count on it, even when he couldn’t count on anything else.

He didn’t think Eren was overreacting to this change in his body. He doubted he could have handled it much better. It was one of the reasons he’d been as sympathetic to Eren as he had. He couldn’t imagine what it would be like to lose the body he’d built over the years--to lose himself. It would be a betrayal, one of the worst he could imagine.

He let Eren keep his shorts on, and slowly moved him to the bed. The sheets were clean, and they smelled like sun and fresh air.

Eren liked the feel of them against his skin. Textures felt different in this body--not sharper, exactly, but as though he were more sensitive, like he could feel more of them. Most of the time it was uncomfortable, but right now it was _amazing_. He was still taller than Levi, but Levi was bigger than him otherwise--heavier, and stronger, and he liked feeling Levi’s body pressed over his. Levi was squishing him, just a little bit, and he liked that. He liked it a _lot_.

He’d been a little terrified when he’d felt Levi’s cock in his hand, and maybe it was just one of those differences in this body because he didn’t _think_ Levi could be huge--not _really_. But the idea of fitting that--into _his_ body--was frightening. It gave him a new appreciation for what girls--real girls--had to go through.

But now with Levi lying over him, pressing him into the mattress with his heavy body, he thought maybe he could start to see how it would be okay.

He really hadn’t expected this at all. He hadn’t thought Levi would agree to this--it had taken him days to work up the courage to even ask, and only today’s failure had made him decide to do it, out of desperation. He’d still thought Levi would say no, or if by some miracle he had agreed Eren had been expecting a really quick and perfunctory five minutes. 

He hadn’t been expecting this. He hadn’t thought Levi would take care of him like this, patient and gentle, and it frightened him a little the same way it had frightened him when he had touched Levi earlier.

Not that he was afraid of Levi. No. He was afraid of himself.

Levi had moved down his body, to kiss his breasts, and Eren was a little stunned by how good it felt. He had tried playing with them on his own--they _were_ nice breasts--but he’d gotten nowhere fast. It hadn’t really felt good--just sort of ticklish and uncomfortable.

Whatever Levi was doing felt _really_ good. He was kissing slowly, all around Eren’s breasts, like he wasn’t in any hurry.

And it was good, but it was--it was starting to--

He arched up a little, hoping Levi would take the hint, but it was still another few minutes before Levi even got close to his nipple. During that time he’d started grinding himself against Levi’s thigh, without even realizing it.

When Levi finally closed his mouth around Eren’s nipple he almost started crying in relief and pleasure. Levi sucked, and Eren didn’t have to tell him harder or slower or anything because everything he did was perfect.

He wiggled under Levi--he took Levi’s hands and brought them down to the underwear he still wore, and Levi took the hint and peeled them off of him.

Eren felt it again--that thrill of fear and anxiety. He’d thought he’d been ready, but--

Levi reached down and gently stroked a hand through the curls on his pubic bone, reached through the softness to touch him _there_ stroking sweetly through the soft, wet flesh. Eren cried out and arched up. Suddenly having his nipple sucked and licked felt _so much better_. Everything ratcheted up to a new intensity.

He’d never made it this far touching himself. He’d never really gotten wet--never mind this, totally soaking and dripping onto the sheets, and Levi would probably be mad about that later--

Levi didn’t push him. He just stroked delicately, making Eren shiver and squeal, wrapping his legs around the outside of Levi’s.

He’s still not--he doesn’t think he’s--

Eventually Levi stopped touching him and moved a little, and Eren swallowed, tensing up. Levi kissed down his body, and Eren relaxed, confused but--

Levi licked him. Licked around, then up, running his tongue carefully over the silky folds of Eren’s new body.

Eren was so open then. It was like the final switch had been turned on, and he’d gone from half-fearful to _ready,_ not just wanting sex but _aching_ for it, feeling empty and wanting to be _filled_. He squeezed Levi’s ribcage with his legs, squirmed and wiggled until he’d gotten Levi where he wanted him, back on top of him.

Still Levi made no move to push into him. He went back to kissing Eren’s neck, which was nice, but not really--

Tentatively he squirmed some more until the tip of Levi’s cock was brushing against him, the smooth head rubbing against the outer folds of his labia. It was--it didn’t feel like anything else. It was a little like being tickled, and like scratching an itch at the same time--and like something else completely.

Levi’s breathing had slowed, but Eren was too busy to notice, and Levi was holding himself still. Eren hadn’t noticed that either. With his usual determination and stubbornness he was trying to work Levi in to him--he hadn’t used his hands, he hadn’t thought to--so he was arching his hips up instead, pushing himself onto Levi one centimeter at a time.

He didn’t think about what he was doing--he was just chasing that amazing feeling, wanting _more_ of it.

Levi let Eren work him at his own pace, though it was sweet torture to stay so still when his body was crying at him to move, to thrust forward and fill Eren up, to impale him and pleasure himself in that sweet body.

He kept still. He didn’t take any pleasure in knowing he was Eren’s first; he wasn’t that sort of man. He would have preferred it if Eren had figured out sex with someone his _own_ age. In spite of that, he was aware that he was receiving something precious. Eren's _trust._ He was resigned to being responsible for Eren, and he knew exactly what it had taken for Eren to ask him to do this. Making sure sex was a positive thing for him, even in these bizarre and exigent circumstances, making sure he was okay and didn't wind up emotionally scarred from the whole thing wasn't something he took lightly.

He braced himself over Eren, keeping still. It was harder than he would have thought. It’s just been a long time, he told himself calmly, _definitely not panicking_. That was all it was.

When he was in Eren all the way, when Eren had pushed himself all the way onto his cock he groaned out loud, dropping his head forward.

Eren wrapped his legs around Levi’s.

“I want you to move,” Eren said, sounding almost shy. He’d heard Levi groan. He’d understood what it was--real pleasure--but more than that denial, and it had made him feel powerful.

He hadn’t felt that in a while.

Levi pulled back, not needing any more urging. He had a lot of good intentions…

Oh holy fuck it was good. He grabbed Eren’s thigh, roughly drawing it up, and Eren shivered in happy pleasure beneath him. It was the first time that Levi had touched him in passion, forgetting to be gentle.

Levi thrust forward, using his grasp on Eren as leverage. Eren’s body was a wet, hot sheath around him, gripping him perfectly, and he knew he was going a little too fast, a little too hard…

Except that Eren was meeting his thrusts, and when Levi pushed in him all the way he’d cant his hips up in a tiny little thrust to get Levi _even deeper_.

He had forgotten almost everything except the hot sweet body thrusting up against his. He kissed Eren deeply, sweetly, thirstily, and he grabbed one of Eren’s hands and pressed it between their bodies.

 _Here,_ he showed Eren where to touch, pressed his fingers to the little nub of his clitoris. Eren rubbed the spot, his fingers slick with wetness. He experimented with stroking himself there, in time with Levi’s thrusts, and felt his whole body start to tighten and stiffen.

Levi must have felt it too. “Oh, fuck, yes,” he said, sounding drunk with pleasure, and he hadn’t been using his full strength before but he did now, gripping Eren’s thigh hard enough to bruise and pounding into him.

It was exactly what Eren would have asked him for if he’d been able to speak, but he couldn’t; he was just moaning and crying--he grabbed Levi’s ass with his free hand and held him tighter, not letting him pull out all the way between thrusts.

He felt--he felt really close to something. “Don’t stop,” he begged.

He touched himself faster and then he felt it, crashing into him and lighting up every part of his body. He shivered, again and again, his body tightening and clenching involuntarily around Levi’s cock.

It went on for a really long time. “Oh my god,” he muttered, dazed, when he finally finished.

Levi pulled out of him and grabbed himself, squeezing, and Eren watched in fascination as he came in about three seconds, hot sticky fluid splattering against his belly.

“Goddamnit,” he said, shaking, and he collapsed next to Eren, burying his face in the pillow.

He sounded wrecked. For the first time in the last half hour Eren started to feel uneasy--a little nervous.

“Was that--okay?” he asked, hoping Levi would say something reassuring.

“Don’t fuck around,” Levi told him, sharply; he sounded almost afraid.

Eren swallowed. Did that mean yes? It had felt--well, he’d thought it had been really good, but what did he know…

“What are you doing?” Levi said, after a while, and Eren flinched. “Why are you still here?”

It was like having ice water dumped over you; Eren sat up, feeling slow and stupid, and Levi said, “You have to go pee, don’t they teach you anything?”

“I--what?” he said, momentarily diverted by this non-sequitor.

“Go pee!” Levi said. “You have to go pee after sex, when you’re a girl--” he waved vaguely at Eren’s crotch-- “It cleans you out, so you don’t get an infection. Hurry up,” he added.

Eren got up--he was too nervous and off balance to grab his clothes, so he left without them, shivering in the cold air as he ran down the hall to the bathroom. At least no one else was up here except for them to see him making an ass of himself. He peed, shivering and naked in the dark, and then he wondered what he was supposed to do next.

Was he--Levi hadn’t said for him to come back. 

He shivered and stood in the bathroom for a minute, feeling stupid and young and tired and ready to burst into tears again. Then he went into his room and laid down in the bed, curling up on himself.

Ten minutes went by, and then the door opened and Levi walked in. He still didn’t have any clothes on. He pulled the blanket back off of Eren, and picked him up, and carried him back down the hallway. 

“I didn’t mean don’t come back,” Levi grumbled.

“Oh,” Eren said. He put his arms around Levi’s neck, for lack of anything better to do with them. Levi put him gently back in his own bed, and Eren noticed that he’d changed the sheets. He moved over to make room for Levi.

“Was that--is that how it always is?” Eren asked after a little while.

“No!” Levi said. “God, fucking no. That was not. Don’t expect that.”

Eren laid there in confusion, wondering if Levi meant--don’t expect it again from him? Don’t expect it to be that good with other people?

Cautiously, he reached out a hand to rest on Levi’s stomach and he felt the older man trembling. Levi didn’t say anything about it, so Eren flattened his hand against him and moved it down--until he had Levi’s cock in his hand. He was rock hard again.

“Do you want to do it again?” he asked.

 _”Yes,”_ Levi said, and he rolled over onto Eren.

This time he didn’t give Eren as much time to prepare; he was frantic, kissing and rubbing against him, and Eren still wasn’t totally clear on what was going on but he was starting to think that with enough practice he would probably be able to figure it out.

He was still wet and slick, and he guided Levi back into his body. It felt good. The first orgasm he’d had had taken the edge off, and he was more relaxed about Levi fucking him this time. He liked being able to feel every stroke, and he liked how the pleasure built slowly, different from the frantic rush it had been before. His second orgasm took a lot longer; it seemed to start somewhere in his toes or behind his eyes, taking its time to build up to a crescendo. It wasn’t as intense as the first one had been, but it felt good in a different way. As soon as he’d finished Levi pulled out to jerk himself off again.

He hadn’t meant to start anything again after he got back from the bathroom (unprompted this time). He’d only wanted to kiss Levi--except that had gotten him interested again, and this time he was on top.

Levi, he noticed, was half-hard again.

“Stop, stop,” Levi said, eventually pulling Eren off of him. “You have to stop, you’re going to be so sore tomorrow--”

Eren shook his head. He’d felt something--a sweet ache that had faded within minutes, both times. “My healing,” he explained, and Levi groaned, covering his eyes with one hand.

“Fuck, you’re going to kill me then,” he said, and he dragged Eren back on top of him, and let him ride him until the sun came up.

 

 

 

The next time Eren transformed he was still a girl. But Hanji had more ideas. 

“Did you try--” she’d say, and Eren would dutifully appear at Levi’s door, with her suggestions in hand.

Eventually he stopped using Hanji as an excuse. Most days they had sex two or three times--at night, in the morning (Eren had given up on sleeping in his own room), and in the afternoon if they could find time to slip away together for a few minutes.

It was still amazing. If anything it was getting better. 

Eren had never imagined he'd be seeing Levi like this--and his private fantasies had been way off. Usually he started off tightly controlled--and every touch of their bodies was a layer of that control peeled back--slowly revealing the real person underneath.

When they weren't having sex Levi let him hang around. If he was reading in bed he'd let Eren lie next to him, his head on Levi's shoulder.

“You could get your own book,” Levi said. He spent so much time staring into space he was starting to seriously question Eren's intelligence. 

“I'm fine,” Eren said.

What he was actually thinking was that this would end eventually. He wanted to soak up as much of it as he could before then. If he hadn't been hopelessly in love with Levi before then he definitely was now. 

Levi was glad that Eren and Jean had had their fight before all this had started. He knew he would beat the snot out of him if he laid a finger on Eren now, with exactly zero remorse. It wasn’t exactly the kind of behavior appropriate to his station, but he accepted it resignedly. 

 

 

There was one night Eren didn’t turn up in Levi’s room. Eventually he went looking for him.

He didn’t have far to go, though--Eren was in his own room, down the hall, looking even more miserable than usual.

“Did somebody say something to you?” he asked gently, feeling homicidal.

Eren shook his head, but he looked close to tears. In spite of all the frustrations Levi hadn’t seen him cry since that first time, weeks ago. He came to sit down next to Eren on the bed.

“What happened?”

“I’m--I’m--I’m--” Eren said, and he covered his face with his hands. “Bleeding,” he said under his breath.

“Oh,” Levi said, relieved. “Well, you know what to do, don’t you…?”

“Yes! The girls already told me,” he muttered.

“Then what’s the matter?”

Eren looked at him, and saw that Levi was genuinely concerned, but that was all.

“I--” he said, and sat there, feeling awful.

“Hmm,” Levi said, looking at him thoughtfully. “We can still have sex. It might even be better for you.”

“But--!”

“It won’t hurt,” Levi said, getting up to stand by the door.

“But--but--it’ll be messy!” Eren protested. Levi was the one who hated dirtiness!

Levi shrugged, indifferently. “Sex is messy. That hasn’t bothered you before.”

“But this is different! There’ll be blood everywhere!”

“Oh, Eren,” Levi said, giving him an amused look. “You think no one’s ever had this problem before? I have some dark towels. Come on.”

“But it’s gross,” Eren wailed, following him.

“Seeing you turn into a Titan is gross,” Levi said. “This is normal.”

“Not for me!”

“Well, maybe it’ll give you a broader perspective on life when you turn back,” Levi said easily.

They were back in Levi’s room. He pulled the covers back on the bed and went to the wardrobe, moving some things around before pulling out a few big black towels and spreading them on the bed.

“Are those--do you do this a lot?” Eren demanded. He hadn’t thought Levi had had relationships with anybody in the Corp--had he been wrong about that?

“No, moron,” Levi said, looking at him almost with affection. “They’re for when I get hurt so I don’t bleed all over the other ones.”

“Oh,” Eren said.

Levi looked at him for a moment, head cocked, and then he came over to put his arms around him. Eren lowered his head to rest on Levi’s shoulder.

“I’m sorry I’m a moron,” he muttered.

“It’s okay.”

“Do you really think I will change back?”

“Yes,” Levi said, so calm and serenely certain that Eren relaxed into him.

Levi ran his hands up over his back, under his shirt to rub his bare skin. 

“There’s one other thing,” Levi said. “I can finish inside you now. It’s safe. If you want.”

“Yes,” Eren said, immediately, his whole body suddenly clenching in a crazy sweet rush of anticipatory pleasure. That was one thing he thought girls had better--when you were a guy you just got erections at inconvenient times, but as a girl he could be turned on without it being obvious to anyone. He forgot about his embarrassment in his eagerness to get them into bed.

Levi was gentle with him, rubbing his breasts softly and kissing all along his neck. Eren reached down to wrap his hand around Levi’s thick cock and dragged the head against the folds of his slick, wet flesh. Levi rubbed against him with a pleased little, “Hmm,” not penetrating, but teasing; the head of his penis gliding over Eren's clitoris and labia.

Eren spread his legs invitingly, and Levi bent his head to kiss and suck at Eren’s breast, keeping the pressure light, while he kept teasing him with his cock.

He writhed around under Levi's expert hands. When he couldn't take it any more he grabbed Levi and kissed him hard, wrapping one leg around the back of his thigh. Levi dipped forward, pressing the tip of his cock in, withdrawing, and pressing in again; moving a tiny bit further with each thrust until he was all the way inside Eren’s body.

He rolled them to the side then, so that Eren was still on his back but he was taking some of Eren’s weight, and he could cup Eren’s ass with one hand. He couldn’t thrust as deeply from this angle, and he kept up the slower pace for a while, kissing and caressing. 

Eventually Eren pulled him back so that he was on top again. They’d tried plenty of different positions in the past few weeks, but they usually ended up back here. It was easy for both of them to climax like this, and there was a natural parity to it that they both liked.

“Harder,” Eren said, pulling Levi close. He slipped a hand between them to touch his clitoris, feeling the pleasure of everything intensify a thousandfold. Levi thrust harder, using the full weight of his body to drive into Eren, making him cry out. Levi was shaking in his arms and kissing Eren harshly. Eren felt himself getting closer, his body stiffening against Levi’s powerful thrusts.

“Yes, yes,” he said, and he arched up, touching himself and letting the motion of Levi’s body carry him through to his own orgasm, pushing him off the sheer edge of the cliff into bliss. Levi thrust a few more times, and then he shivered, and Eren felt him pulse within him, and heard him gasp.

No matter how good the sex had been before he’d been a little unhappy that they hadn’t been able to do this; it had felt unequal, like he had the advantage over Levi. He found himself feeling warm and unreasonably happy after, clinging to Levi, kissing and petting. 

“How long can we, um.”

“It depends how long you bleed for,” Levi said. “The next couple of days, probably.” He pushed Eren off of him, and Eren reluctantly got out of bed to go and clean up. When he came back Levi had straightened out the bed, and he went to go and use the bathroom next.

Eren was curled up on his side of the bed when he came back.

“Hanji wants to do more experiments the day after tomorrow,” he said glumly when Levi was back in his arms. “I think she’s out of ideas.”

“She’ll think of something,” Levi said, stroking his hair. “Don’t underestimate her.”

Eren nodded and turned over, and Levi wrapped his arms around him from behind, and they went to sleep.

 

 

 

They took full advantage of Eren’s temporary affliction, and the morning of Hanji’s planned experiments Eren was feeling pretty cheerful, if not exactly hopeful. 

At least it would be over soon, and then he’d have another day or two of freedom in bed with Levi before they had to go back to Levi pulling out at the end.

He went through a bunch of Hanji’s instructions, in the female Titan body that had become familiar to him by now. They spent the morning running through things, and then she called for Eren to transform.

He did, pulling himself easily out of the Titan on his own. When he stepped out of it and jumped down to the ground he nearly fell over--suddenly he felt a lot heavier than usual.

He looked down at himself, and then he stared. The shirt and pants were loose on him--they didn’t fit his flat chest and narrower hips as tightly. He patted his chest--it felt strange, without the two mounds of his breasts--and then he touched his groin--just to make sure everything was still there.

He looked up, staring at the others in shock. Hanji screamed in delight and ran over to embrace him, jumping up and down.

“Eren! Eren what happened! Did you do something? You changed back!”

He swallowed and couldn’t help but glance over at Levi. He saw the faintest glint of amusement on Levi’s face, and saw that he was thinking the same thing Eren was; there was only one thing he’d done differently lately.

He should have been thrilled. And he was happy--he wouldn’t have wanted to be stuck in the other body forever. But it felt so sudden, and at the same time so anticlimactic. And he’d grown more used to the other body than he’d realized. Now his old body felt heavy and plodding and ungraceful.

His friends were delighted for him, and he had to lie to them about how happy he was. He packed up his things and moved back into the boys’ dormitory as soon as he got back, figuring there was no sense in postponing it.

That night before bed he took a shower alone in the communal washroom. He took the time to examine his body--in a way he hadn’t ever done, when he’d just been uncomplicatedly male. Everything was flat and hard and angular. He tried to jerk off, but he could barely even get an erection and after a few minutes he gave up in frustration, leaning against the tile wall, wondering if he was ever going feel normal or comfortable in his own body ever again.

 

 

 

They didn’t talk about it. Levi knew he’d gone back to the boys’ room, and he didn’t say anything about it. They didn’t talk about anything personal or private. Things were like they had been before--Levi went back to treating him like a subordinate, and Eren went back to calling him ‘Captain.’

Eren didn’t know if Levi missed it. He tried to behave normally though--he was back to his regular, normal level of freakishness and he was determined to keep it that way for as long as possible--but he couldn’t help but feel that everything was all wrong.

Levi caught him getting frustrated using the 3DM a few days after he’d changed back. They were out training in the woods, and he’d gotten tangled up in his wires, like a stupid trainee. Fortunately no one had been around to see, though he could hear the others not too far off. He struggled to free himself before anyone noticed.

Levi landed lightly beside him, and untangled him without a word.

He breathed out--embarrassed but grateful--and let Levi pull him aside.

“Go easy on yourself,” Levi said. “You don’t need to get back to where you were in a day.”

Eren shrugged, his cheeks burning.

“It took you time to get used to the other body,” Levi said. “You just have to do that again.”

Eren nodded, but he privately wondered if this were true. He still caught himself thinking as if he were in the female body--and dreaming as if he were. The worst part was, he was growing less sure, less confident, that he wanted to be changed back. He’d never thought about his body before--and now he couldn’t figure out how it worked. It didn’t feel like it belonged to him any more.

“Eren,” Levi said gently, and when he wouldn’t look at him Levi took his chin in his hand and tilted his head up. It was the first time they had touched since the change, and Eren shivered involuntarily.

Well, that was one question answered at least.

“I’m here, if you need help,” Levi said, and then he flew off, leaving Eren behind to catch his breath. When he was alone he had to adjust himself uncomfortably--it was the first erection he’d gotten since changing back.

 

 

 

After a week or so Eren seemed to be getting into the groove of things. Hanji had more or less given up on trying to get an answer out of him for why he’d changed back, and he was relieved when she finally dropped it. He really didn’t want to have to say ‘Levi’s magic semen’ (though who knew--probably anybody’s would have worked). Although, really, what the hell? Had it just jumpstarted his body? Reminded it ‘Oh, hey, yeah, hmm, we’re supposed to do that, right.’ Hanji might have had a theory about it, but he didn’t think he actually wanted to know badly enough to have that conversation.

He’d never told Hanji who it was he’d been having sex with. He would have thought she’d know anyway--been able to guess, but it was Hanji, so…

He still didn’t really feel comfortable in his body. It had started to move again like he remembered, but once again he’d had to give up in frustration on trying to figure out what brought him pleasure or made him comfortable.

He missed Levi.

One night Levi came out of his room to find Eren lurking in the hallway, sort of hand-wringing and possibly working up the courage to knock. 

He stared at Eren for a moment, then said, “I’m going to brush my teeth.”

Eren stared back, and nodded.

When he came back a few minutes later Eren was still there, looking perhaps marginally less terrified. 

“Well?” Levi said, stopping in front of him.

“Do you want to--um,” Eren said, courage deserting him.

Levi looked at him for a beat, then said, “Yeah, okay,” and let him in.

And Eren was very happy to find out that everything still worked after all, maybe even a little better than he remembered.

**Author's Note:**

> Haha, so okay, this was the story I wasn't going to write because I thought it was too silly, but bits and pieces of it kept coming, and come on, who doesn't enjoy a good cliched genderswap from time to time? :D 
> 
> There may or may not be an alternate ending I post at some point with even MORE crack!cliches, but I should probably get back to finishing my superserious angst fics first ;)
> 
> Comments are <3


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